another way to tell, if you can put a socket on the bottom bolt, under the driveshaft on the face plate it is 9",
if you can put only a wrench, 9 3/8"

 

You can change the steering wheel, not the shaft.

Like Bill said earlier, prior to 65, the shaft goes right into the box, after 65, there is a rag joint between the shaft and the box

 

So is there a possibility that this is the original frame?

 

My bad - I was looking at the front hub and didn't realize it.

 

I would imagine the frame is origional, drivetrain could be changed, but it could also be aftermarket, like Marmon Herington

Give us a picture of where the steering column goes into the box